Cost-Effective Enhancement of RF Switch Performance Utilizing Novel Coupling Structures

Radio frequency (RF) switches are essential for efficient and reconfigurable RF systems and emerging technologies. This includes reconfigurable intelligent surfaces (RISs) and antennas in future sixth-generation (6G) networks. This article introduces novel coupling enhancement structures (CESs) to cost-effectively enhance switch performance. The CES method is adaptable to various RF switches, improving metrics such as isolation, especially in higher frequency bands. Designed as subwavelength metal patterns, CESs counteract adverse parasitic effects and can be fabricated cost-effectively with circuit boards. An efficient analytical method based on multiport network theory optimizes CES performance, reducing the computational demands of full-wave electromagnetic (EM) solvers. A dc control algorithm manages potential short circuits caused by CES, ensuring effective control with CES. Prototype and experimental verification using p-i-n diode prototypes in millimeter-wave (mm-Wave) and sub-6-GHz bands demonstrate significant performance enhancements with optimized CES. The proposed CES approach offers a promising solution to the cost and performance limitations of high-frequency RF switches, facilitating their effective use in advanced communication systems.